Comprehensive and Integrative Experimentation Setup for Large Animal Hybrid Valvular Heart Surgery.

BACKGROUND: Experimental surgical procedures for atrioventricular valves present promising translational capabilities, and preclinical studies are necessary to assess their applicability and to train young enthusiastic heart teams. Here, we present a synopsis of experimental surgical procedures on porcine models for mitral valvular (MV) and tricuspid valvular (TV) interventions; mitral valve-in-valve implantation (MViV), transapical cardioscopic (TAC) MV replacement (MVR), TAC-MV annuloplasty, and tricuspid valve-in-a-ring (TViR) procedures. METHODS: Twenty-five (n = 25) female Yorkshire pigs of 55-65 kg is the total number used in the four approaches; seven animals underwent MViV, six TAC-MVR, six TAC-MV annuloplasty, and six TViR, respectively. All were subjected to a first conventional valvular surgery (bioprosthetic valve replacement and/or prosthetic ring repair). Then, after 4 wk, a less-invasive second surgery was performed using the transcatheter approaches under investigation. Except for the TAC-MVR and annuloplasty procedures, all animals were followed up for additional 4 wk. RESULTS: (1) MViV (n = 7): Standard MVR was successfully performed in all animals. Transvalvular pressure gradients and flow velocities were (Pmax 3.77 ± 0.8 mmHg; Pmean 2.1 ± 0.6 mmHg, Vmax 97 ± 13 cm/s; Vmean 68 ± 21 cm/s). Effective MViV followed (Pmax 16.7 ± 1.8 mmHg; Pmean 6.2 ± 1.2 mmHg, Vmax 216 ± 32 cm/s; Vmean 110 ± 24 cm/s). (2) TAC-MVR (n = 6): The overall bypass time was 177.2 ± 44.2 min. Transprosthetic Pmean was 4.6 ± 2.4 mmHg; no paravalvular leaks in all animals. (3) TAC-MV annuloplasty (n = 6): The implantation time was 47 ± 6 min. MV was competent, left ventricular ejection fraction (LV-EF%) was 63 ± 4%. (4) TViR (n = 6): Conventional TV ring repair was performed in all animals (Pmax 2.42 ± 0.7 mmHg; Pmean 1.3 ± 0.6 mmHg, Vmax 82 ± 10.4 cm/s; Vmean 65.4 ± 21 cm/s). All TViRs were implanted efficiently (Pmax 4.7 ± 1.6 mmHg; Pmean 2.7 ± 0.8 mmHg, Vmax 105 ± 31 cm/s; Vmean 81 ± 16 cm/s). A mild paravalvular leak was observed in one animal (16%). CONCLUSIONS: All studied experimental valvular interventions are feasible, within the context of well-trained cardiac surgery specialists, and all possibilities should be considered when treating a patient to determine which one suits best his individual challenges and scope.

IGF-IEc Expression Is Associated With Advanced Differentiated Thyroid Cancer.

BACKGROUND/AIM: Recent knowledge implicates a differential expression of the insulin-like growth factor-I (IGF-I) mRNA splice variants (i.e., IGF-IEa, IGF-IEb and IGF-IEc) in cancerous tissues, implying possible specific roles of the encoded IGF-I protein isoforms in cancer biology. In particular, there is growing evidence that the IGF-IEc isoform may play a distinct biological role in various types of cancers. The present study investigated whether IGF-IEc expression is associated with a particular type of thyroid cancer. MATERIALS AND METHODS: Formalin-fixed paraffin-embedded tissue specimens of different types of thyroid cancers from 92 patients were assessed for IGF-IEc expression by immunohistochemistry. In addition, thyroid cancer biopsies of different TNM staging histological types were evaluated for mRNA expression of the IGF-IEc transcript by real-time polymerase chain reaction (PCR). RESULTS: From the total number of 92 samples, 2 were anaplastic, 10 medullary, 4 hyperplasias of C-cells, 11 follicular, 5 hurtle cell carcinomas, 2 poorly differentiated, 5 nodular hyperplasias, 1 lymphoma and 52 were papillary thyroid cancers. The age of cancer diagnosis or tumor size did not significantly affect the IGF-IEc expression. Among all types of cancers, IGF-IEc was expressed in papillary differentiated thyroid cancer. Its expression/localization was mainly cytoplasmic and significantly associated with TNM staging and the presence of muscular and capsule cancerous invasion (p<0.05). Similarly, a differential profile was revealed regarding the mRNA expression of the IGF-IEc transcript, that exhibited a higher expression in aggressive compared to the non-aggressive papillary cancers. CONCLUSION: IGF-IEc isoform expression in thyroid cancer is positively associated with more advanced stages of papillary thyroid cancer.